For the GFS2 filesystem to be mounted on multiple nodes, you must ensure that the total number of Filesystem journals is equal to the number of nodes. The number of available journals may be insufficient to successfully mount the GFS2 fs on all nodes of the cluster after a new node has been added. To …
Category: Linux
How to disable or enable the IPv6 protocol in AlmaLinux?
Why errors are received when changing IPv6 kernel parameters? # sysctl -p error: "net.ipv6.conf.default.accept_redirects" is an unknown key error: "net.ipv6.conf.default.accept_ra" is an unknown key error: "net.ipv6.conf.all.disable_ipv6" is an unknown key error: "net.ipv6.conf.default.disable_ipv6" is an unknown key Internet Protocol Version 6 (IPv6) is enabled by default in AlmaLinux and CentOS. However, some users might find it …
Physical volumes for the VG are present in lsblk and lsscsi but not found by LVM2
Run the command vgimportdevices -a if every drive on the AlmaLinux server is a PV that this system can use. Only the multipath map will be added by vgimportdevices -a if a LUN is multipathed. Run lvmdevices --adddev [device name] for each device that will be used if just part of the disks contain the …
How to configure CentOS to accept LPD connections from Unix clients?
The cups-lpd package must be installed and set up in order to accept requests to print using the LPD protocol on port 515. (in addition to a properly configured CUPS system). In all versions of CentOS, first install the cups-lpd package as follows. yum install cups-lpd Depending on the CentOS version you are using, there …
How to configure CUPS to use ephemeral ports instead of reserved ports?
When many users are printing at once, CUPS is very slow. The following error is seen repeatedly in the file /var/log/cups/error_log. E [09/Jul/2013:10:06:00 +0200] [Job 865106] Unable to reserve port: Resource temporarily unavailable The firewall blocks connections initiated from low-numbered TCP ports (port numbers less than 1024). This blocks CUPS outgoing LPD (Line Printer Deamon) …
Failed to load SELinux policy, freezing: System cannot boot
The root cause of this error is that the policy file is corrupted or empty. After turning on SELinux, the system is unable to boot. The screen displays the following messages and the booting process does not continue. [ OK ] Reached target Switch Root. Starting Switch Root... [!!!!!!] Failed to load SELinux policy, freezing …
How to change existing print queue to send data to a file instead of to physical printer?
To set up a print queue that will send the print job to a file, carry out the following operations as root. Add the following line to /etc/cups/cupsd.conf in CentOS 4, 5, or 6, or to /etc/cups/cups-files.conf in CentOS 7 and 8. FileDevice yes Restart the CUPS service. service cups restart Use a command akin …
32-bit application not finding files on XFS filesystem
Inodes received 32-bit numbers or less under older XFS behavior, which always allocated inodes within the first 1TiB of the filesystem. With more recent XFS behavior, inode64 is the default mount option, allowing inodes to be put anywhere inside the filesystem. However, files with inode numbers greater than 32 bits may be difficult for 32-bit …
How to install rasdaemon and monitor hardware errors
To set up the hardware error reporting rasdaemon. Install the rasdaemon package first. Launch the rasdaemon service after enabling data collection in Rasdaemon. Configure the rasdaemon service to restart automatically when the computer boots up. The motherboard DIMM labels can be imported into the EDAC drivers once the service has been launched for simpler fault …
How to configure a Samba server with SSSD in CentOS 7 or 8
The idmap sss module has some restrictions when used with CentOS 7. As a result, it is currently not advised to utilize the idmap sss module for Samba file servers registered with AD domains. If you are configuring a CentOS 8 or above version, you must run the following command. The system must be rebooted …
How to set the variable $PATH when executing the csh via rsh
In CentOS 7, add setenv PATH <PATH string, use \: to split> when executing the csh command as below. [testuser@centos7~]$ rsh remotehost 'echo $PATH' /usr/bin:/bin [testuser@centos7 ~]$ rsh remotehost 'setenv PATH /usr/bin\:/bin\:/opt;echo $PATH' /usr/bin:/bin:/opt
Why does CentOS 6 to 7 upgrade fail if /usr is on separate partition ?
Due to technological restrictions, upgrades are not supported if /usr or child folders are distinct partitions from /. It is a fixed condition that cannot be altered. The whole contents of the /usr partition can be moved to the /usr directory using rescue mode as a solution. The contents of /usr can be online relocated …
Is systemd-resolved enabled in AlmaLinux 8?
At the time of writing, the systemd-resolved service is only available as a Technology Preview on AlmaLinux 8 and AlmaLinux 9. Technology Preview features might not be complete, are not covered by SeiMaxim's production Service Level Agreements (SLAs), and SeiMaxim does not advise utilizing them in production. Customers can test functionality and offer feedback while …
File systems became read-only on virtual guests on VMware
Filesystem entered ready-only mode, and the following SCSI I/O fault incidents were recorded in syslog messages. kernel: sd 0:0:0:0: timing out command, waited 1080s kernel: sd 0:0:0:0: Unhandled error code kernel: sd 0:0:0:0: SCSI error: return code = 0x06000008 kernel: Result: hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT,SUGGEST_OK If the failover occurs before the timeout, everything will proceed as usual. …
How to create custom email template in Alertmanager?
Configure your email receiver to, for example, display the email's subject in the headers section and its template-based body of text. receivers: - name: EmailReceiver - to: myaddress@example.com headers: subject: 'Summary: {{ .CommonLabels.alertname }} {{ if eq .Status "firing" }}(Firing){{ else }}(Resolved){{ end }}' html: '{{ template "emailcontent.txt" . }}' As indicated below, add the …
